Connecting with private ip

I am using the Centos 6.3 image. I want to connect my VMs via private ip but cannot get it work.

I already open the relevant port and for my iptables I added

iptables -I INPUT -p tcp -m tcp -s 0.0.0.0/0 --dport 11211 -j DROP

iptables -I INPUT -p tcp -m tcp -s 10.2.3.11 --dport 11211 -j ACCEPT

(I do need the first drop rule for some ports)

What is wrong with my second rule? If I replace the private ip with public ip and I can actually connect with the public ip.